The main objective of this study was to produce flame retardant polyamide-6 (PA-6) and polypropylene (PP) composites and fibers containing boron compounds. The synergistic effect on flame retardancy of boron compounds (boron silicon containing oligomer (BSi), zinc borate (ZnB), boron phosphate (BPO4), metal oxide doped BPO4 and lanthanum borate (LaB)) with conventional flame retardants were investigated. The synergistic effect of nano-clay with commercial flame retardants was also investigated in order to reduce the total amount of flame retardant that is essential for fiber applications. The UL-94, limiting oxygen index (LOI), differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA), fourrier transform infrared spectroscopy (FTIR) and cone calorimeter tests were conducted on composite materials in order to investigate the effect of synergy agents on the flame retardant and thermal properties of conventional flame retardant containing PA-6 and PP composites.
According to the results from composite materials, boron compounds and clay showed synergistic effect with phosphorus based commercial flame retardants by acting generally with a condensed phase mechanism by increasing the char formation and/or by increasing the barrier effect of the final char residue.
Inspired from the previous studies, firstly, only nano-sized BPO4 containing flame retardant fibers were produced and characterized. In the view of the results obtained from the composite trials, the boron compounds and organo clay were used with phosphorus based flame retardants to produce flame retardant fibers. The characterization of fiber samples were made with mechanical testing, melt flow index measurements (MFI), TGA, DSC, SEM and Micro Combustion Calorimeter (MCC) tests.
According to the results from fiber samples, the inclusion of BPO4 reduced the peak heat release rate of the pure PA-6 and PP fiber. The reduction for PA-6 is higher than the PP fiber due to char forming character of PA-6. The usage of boron compounds and clay with phosphorus based flame retardants caused further reduction of peak heat release rate (PHRR) and total heat release values and increased the char formation. The amount of reduction of PHRR and total heat release (THR) is not so much due to the thermally thin character of fiber samples of nearly 40 microns. It is evident that a fabric made with these fibers will show better flame retardant behavior than single fiber tests due to its thick character with respect to the fiber samples.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12613266/index.pdf |
| Date | 01 May 2011 |
| Creators | Dogan, Mehmet |
| Contributors | Bayramli, Mehmet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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